Assay Development
Using recombinant monoclonal antibodies to develop IVDs
The use of monoclonal antibodies in IVD kits and assays has already been well established. However, the development of highly sensitive and specific monoclonal antibody-based detection systems can be hampered by the unpredictability and inflexibility of traditional hybridoma technology. Through significant advances in genetic engineering, creating recombinant monoclonal antibodies is now possible by using well-tested phage display technology. Such antibodies match the strengths of traditionally...
Assessing the future of immunoassays
A report by Kalorama Information (New York), “The Worldwide Market for In Vitro Diagnostic Tests,” concluded that the future for immunoassays is a mixed bag. In the clinical laboratory, mature assays will show moderate growth while emerging assays will fuel most of the growth in this IVD segment. However, all immunoassays will have to pass the test of medical research to demonstrate their contributions to improving patient outcomes. For example, increased knowledge of disease...
Automated quantitative microarray assay platforms
            Figure 1. SQiDworks diagnostics platform. Protein microarrays have become powerful tools for examining various aspects of the immune system. Investigators can now test for the presence of multiple specific (multiplexed) antibody reactivity in patient samples with one reaction by using antigen microarrays spotted on planar substrates.1 For example, such microarrays can identify clinical subtypes of rheumatoid arthritis.2 However, unique...
Introduction to assay system components
      The Exact Volume Pipets by Poly-Pipets Inc. (Englewood Cliffs, NJ) can deliver specific dispensing requirements and are available in drop sizes from 20 ul to 400 ul. While the 1990s may have been the true brink of the point-of-care (POC) era, the new millennium may be the era of mergers and acquisitions. Regardless, modern IVD technologies have changed over the last two decades at a rapid pace akin to the other technology sectors and the pharmaceutical...
Introduction to filters, membranes, and bioseparation equipment
      Membranes and filters are available in a variety of formats and can be customized for diagnostic sample preparation and detection. IVDs based on traditional immunoassay procedures and immunochromatographic test strip materials have long been a hallmark of the biotechnology industry. But recent scientific discoveries, the identification of novel biomarkers indicative of disease, and the increased sensitivity of new detection systems have spurred expansion of...
Introduction to Biochemicals and Chemical Reagents
      Different kinds of chemical and biochemical solutions are used in enzyme-linked immunosorbent assays (ELISA). All IVD assays require chemicals and biochemicals. Choosing and sourcing these components are very important steps in the development and manufacture of any IVD product. The wrong choice of assay buffer, for example, can make all the difference between an assay that performs very well and one that exhibits poor precision or poor sensitivity. Excellent...
Diagnostic approaches to managing West Nile virus
    ASSAY DEVELOPMENT         Figure 1. (click to enlarge) West Nile virus transmission cycle. (Taken from the Public Health Agency of Canada's Web site and reproduced with the permission of the Minister of Public Works and Government Services.) Ever since West Nile virus (WNV)-related cases of encephalitis were first reported in New York City in 1999, which resulted in seven deaths, the virus has become endemic to North America. Clinical management of...
Dominating the market
    EDITOR'S PAGE     Since the 1960s immunoassays have contributed enormously to clinical lab medicine. During the past few years, immunoassays of all kinds (e.g., automated, manual, ELISAs, enzyme immunoassays, bead arrays, microarrays) have dominated the IVD market, and have become one of the primary and indispensable tools in diagnosing and monitoring in all areas of medicine. The market potential of immunoassays is now even greater than before. The publication...
Porous adhesive technology for diagnostic applications
    ASSAY DEVELOPMENT       Adhesives Research's porous pressure-sensitive adhesive forms isolated channels to control flow and movement of fluids or gases. Diagnostic assays are indispensable for detecting such compounds as drugs, hormones, enzymes, proteins, antibodies, and infectious agents in biological fluids and tissue samples. Diagnostic device developers are currently considering ways for increasing assay sensitivity while reducing device complexity...
Affinity discrimination to avoid interference in assays
    ASSAY DEVELOPMENT       Any immunodiagnostic assay can suffer from negative test effects, which fall under the rubric of interference. These effects lead to imprecision or can result in false-positive or false-negative outcomes. False negatives represent the worst case for most clinical diagnostic tests. However, it is hard to routinely detect them. Now, though, a new buffer is available that, used instead of traditional assay buffers, enables most interference...